Receptor Theory Flashcards
What is pharmacology?
The study of drugs in its broadest sense, including the interactions between drugs and body constituents at any level of organization
What are drugs?
Substance that bring biological change through its chemical actions
What is a receptor?
A macromolecular component of the organism that binds the drug and initiates the drug’s effects
What is a cell surface receptor?
A receptor embedded in the membrane and functions to receive chemical information from the extracellular part and to transmit that information to the intracellular part
How does a drug work by antagonizing cell surface receptors?
Attach to a binding site on receptor for agonists to sterically prevent it from binding
Can also bind to a separate receptor in an allosteric effect to displace the agonist
What antagonist is a beta-adrenoceptor blocker for angina, myocardial infarction, heart failure, high blood pressure and anxiety?
Propranolol [Inderal]
What is a nuclear receptor?
A receptor that exists in the intracellular part and is when activated it binds to regulatory regions in the DNA to modulate gene expression
How does a drug work as an antagonizing nuclear receptor?
Binds the drug molecule so the endogenous chemical cannot bind to the receptor and cannot alter gene expression
What drug is a nuclear receptor antagonsist that prevents and treats breats cancer?
Tamoxifen [Nolvadex]
How do drugs work by inhibiting enzymes?
Bind to the enzyme to inhibit the activity so that there is no product
Which drug is an enzyme inhibitor that inhibits cyclooxygenase for pain relief, mostly due to arthritis?
Aspirin, ibuprofen [Motrin]
How do drugs work by blocking ion channels?
Bind to ion channels and physically block the membrane pore to cause an allosteric change to close the pore
What drug blocks ion channels of calcium channels for angina and high blood pressure?
Diltiazem [Cardizem]
How does a drug work by inhibiting transporters?
Bind to transporters and cause allosteric changes that prevent proper function of the transporter and it cannot shuttle solutes
Which drugs are inhibits transporters that are selective serotonin reuptake inhibitors (SSRIs) that treat depression?
Fluoxetine [Prozac]
How does a drug work by inhibiting signal transduction proteins?
Binds to inhibit key signal proteins to keep it from sending a chemical signal from finding its target
What drugs are signal transduction protein inhibitors that inhibit type 5 phosphodiesterase for erectile dysfunction?
Sildenafil [Viagra]
How do drugs antagonise, block or inhibit endogenous proteins?
Antagonists of cell surface receptors Antagonists of nuclear receptors Enzyme inhibitors Ion channel blockers Transport blockers Inhibitors of signal transduction proteins
How do drugs work by activating endogenous proteins?
Agonists of cell surface receptors
Agonists of Nuclear Receptors
Enzyme activators
Ion channel openers
How does a drug work by activating cell surface receptors?
Some drugs are the actual chemical signal
Some drugs mimic the chemical signal
Both will increase the chemical signals that transmit from outside to inside of the cell
What drug is a cell surface activator that is an Alpha1-Adrenoceptor Agonist for nasal congestion?
Phenylephrine [Neosynephrine]
How does an agonist work?
Bind to a remote site on receptor and cause allosteric effect that increases the ability of the endogenous agonist to bind or activate the receptor
How do drugs work by activating nuclear receptors
Increase the chemical (by using that chemical or a mimic) to increase the effect of intracellular chemicals on gene expression
What drugs operate as activators of nuclear recpetors which work as estrogen receptor agonists for hormone replacement therapy in postmenopausal women?
Conjugated equine estrogen [Premarin]
